When valves are to be used in connection with urine bags and other disposable articles, it is important that the valve functions reliably and is easy to operate, even though the valve must be cheap to manufacture. A valve of the above type having a tubular valve housing and a circularly cylindrical valve body displaceably arranged therein is known from, e.g. British patent specification No. 1,310,581. The end portions of the valve body of this known valve have an outer diameter corresponding to the diameter of the longitudinal bore of the housing which receives the valve body so that these end portions are in sealing engagement with the inner wall of the housing, while the central portion of the valve body between these end portions has a reduced diameter. In this known valve the valve body may be displaced between an open position of the valve, in which the central portion of the valve body with the reduced diameter is arranged opposite to a transverse flow passage intersecting the longitudinal bore of the housing, and a closed position of the valve, in which one of the thicker end portions of the valve body is located opposite to and closes the flow passage. This known valve structure has the advantage that its function is independent of the rotational position of the valve body in relation to the valve housing. However, the molding of a valve body with a central portion of a reduced diameter requires the use of a relatively complicated injection mold. Furthermore, in order to obtain a reasonably small flow resistance, it is desirable to make the diameter of the central portion of the valve body relatively small, which may, however, unduly reduce the strength of the central portion of the valve body.
It is also known to avoid the use of a valve body with a reduced central portion by providing the valve body with a transverse bore. In order to ensure that this transverse bore of the valve body is always aligned with the flow passage of the valve housing in the open position of the valve, the valve body must be prevented from rotating in relation to the valve housing. In the last mentioned known structure this is obtained by forming the longitudinal bore of the valve housing as well as the valve body with a cross-section shaped like a circle with a segment cut therefrom. This cross-sectional shape has, however, proved less satisfactory because it requires that the measures of the outer peripheral wall of the valve body and the inner peripheral wall of the valve housing are kept within very narrow limits in order to ensure sealing engagement between these surfaces.